[PATCH] HID: memory leak in dualshock4_get_calibration_data

[Eslam Khafagy]

function dualshock4_get_calibration_data allocates memory to pointer
buf. however the function may exit prematurely due to transfer_failure
in this case it does not handle freeing memory.

this patch handles memory deallocation at exit.

Reported-by: syzbot+4f5f81e1456a1f645bf8@xxxxxxxxxxxxxxxxxxxxxxxxx
Tested-by: syzbot+4f5f81e1456a1f645bf8@xxxxxxxxxxxxxxxxxxxxxxxxx
Closes: https://lore.kernel.org/all/691560c4.a70a0220.3124cb.0019.GAE@xxxxxxxxxx/T/
Fixes: 947992c7fa9e0 ("HID: playstation: DS4: Fix calibration workaround for clone devices")
Signed-off-by: Eslam Khafagy <eslam.medhat1993@xxxxxxxxx>
---
 drivers/hid/hid-playstation.c | 7 ++++---
 1 file changed, 4 insertions(+), 3 deletions(-)

diff --git a/drivers/hid/hid-playstation.c b/drivers/hid/hid-playstation.c
index 63f6eb9030d1..fef81b7e27c1 100644
--- a/drivers/hid/hid-playstation.c
+++ b/drivers/hid/hid-playstation.c
@@ -1992,9 +1992,6 @@ static int dualshock4_get_calibration_data(struct dualshock4 *ds4)
 	acc_z_plus       = get_unaligned_le16(&buf[31]);
 	acc_z_minus      = get_unaligned_le16(&buf[33]);
 
-	/* Done parsing the buffer, so let's free it. */
-	kfree(buf);
-
 	/*
 	 * Set gyroscope calibration and normalization parameters.
 	 * Data values will be normalized to 1/DS4_GYRO_RES_PER_DEG_S degree/s.
@@ -2041,6 +2038,10 @@ static int dualshock4_get_calibration_data(struct dualshock4 *ds4)
 	ds4->accel_calib_data[2].sens_denom = range_2g;
 
 transfer_failed:
+	/* First free buf if still allocated */
+	if(buf)
+		kfree(buf);
+
 	/*
 	 * Sanity check gyro calibration data. This is needed to prevent crashes
 	 * during report handling of virtual, clone or broken devices not implementing
-- 
2.43.0